Source

File: wp-admin/includes/class-wp-terms-list-table.php

private function _rows( $taxonomy, $terms, &$children, $start, $per_page, &$count, $parent = 0, $level = 0 ) {

		$end = $start + $per_page;

		foreach ( $terms as $key => $term ) {

			if ( $count >= $end ) {
				break;
			}

			if ( $term->parent != $parent && empty( $_REQUEST['s'] ) ) {
				continue;
			}

			// If the page starts in a subtree, print the parents.
			if ( $count == $start && $term->parent > 0 && empty( $_REQUEST['s'] ) ) {
				$my_parents = array();
				$parent_ids = array();
				$p          = $term->parent;
				while ( $p ) {
					$my_parent    = get_term( $p, $taxonomy );
					$my_parents[] = $my_parent;
					$p            = $my_parent->parent;
					if ( in_array( $p, $parent_ids, true ) ) { // Prevent parent loops.
						break;
					}
					$parent_ids[] = $p;
				}
				unset( $parent_ids );

				$num_parents = count( $my_parents );
				while ( $my_parent = array_pop( $my_parents ) ) {
					echo "\t";
					$this->single_row( $my_parent, $level - $num_parents );
					$num_parents--;
				}
			}

			if ( $count >= $start ) {
				echo "\t";
				$this->single_row( $term, $level );
			}

			++$count;

			unset( $terms[ $key ] );

			if ( isset( $children[ $term->term_id ] ) && empty( $_REQUEST['s'] ) ) {
				$this->_rows( $taxonomy, $terms, $children, $start, $per_page, $count, $term->term_id, $level + 1 );
			}
		}
	}